“The Tell-Tale Heart” is a chilling 1843 short story by Edgar Allan Poe about a man whose disturbed conscience is haunted by the sound of a heart that will not stop beating. The real-life tell-tale heart is the tragedy of now 14-year-old Jahi McMath, diagnosed as “brain dead” in 2013 but whose heart still beats. The outcome of a July 30 court hearing in Alameda County Superior Court could overturn a half-century of established belief, change medical practice, and haunt the conscience of medicine.

While a brain-dead patient’s heart can beat briefly, Jahi’s heart and blood pressure have been stable for 18 months, something virtually unprecedented with the diagnosis of brain death. The original diagnosis may have been wrong — a disconcerting possibility — or the concept of brain death must be updated for the 21st century.

In December 2013, following a routine tonsillectomy, Jahi suffered a cardiac arrest and brain damage from lack of oxygen to the brain. Neurologists found no demonstration of cerebral electrical activity, no blood flow to her brain, and no spontaneous breathing. She was diagnosed as “brain dead”; a coroner issued a death certificate and the hospital prepared to discontinue her ventilator.

In a legal proceeding separate from the current lawsuit, Jahi’s family fought to keep her on the ventilator. A court-appointed expert who examined Jahi concurred with the brain death diagnosis. Technically, Jahi was no longer a living person.

Jahi McMath

Despite this, her family subsequently received court approval and took her to a New Jersey facility willing to care for her. She is kept on a ventilator and fed through a feeding tube. Her heart has been beating far longer than that of nearly any other brain-dead patient, a troublesome fact most experts have ignored.

When Jahi’s family initially went to court, most doctors familiar with brain death felt the family’s interests, while understandable, should not supersede the law and that the judge’s decision to keep Jahi on a ventilator was wrong. Once Jahi was declared legally dead, conventional thinking was that her ventilator should have been disconnected. Without it breathing for her, her heart would have stopped in minutes. But the possibility exists that the diagnosis was erroneous, and a medical malpractice lawsuit filed in March may revisit whether Jahi is alive or dead.

Here’s why: In cases of properly diagnosed brain death, no patient has ever recovered to come off a ventilator. The heart continues beating only because of the ventilator and drugs occasionally given to sustain blood pressure (usually if patients are organ donors).

However, even in brain death, machines and drugs ultimately will not sustain the heart. Even with patients on the ventilator, the heart usually stops within hours to days, and patients “die” in the widely understood sense. There are occasional cases of pregnant women, brain dead but kept on life support until they delivered. Outside of those, there are only a handful of reports of brain-dead patients on ventilators with heartbeats for more than three months, and in those cases the diagnosis of brain death has been questioned.

Because Jahi’s heart continues beating, the new malpractice lawsuit reopens an area of life and death once thought settled. In California, damages are legally capped for the wrongful death of a child, but with no cap, damages could run into millions of dollars if the child is injured but still alive, as the suit claims. So the court must decide on revisiting the question, “Is Jahi McMath alive or dead?”

Alameda County Superior Court Judge Robert Freedman said in a tentative ruling Thursday that he was inclined to dismiss the part of the suit filed in Jahi’s name, presumably because a dead person cannot file suit.

Unlike the cases of Terri Schiavo and Karen Ann Quinlan, who were not brain dead and could breathe without ventilators, the question here is not strictly whether Jahi will regain consciousness but the meaning of brain death as death of a person, and whether traditional diagnostic criteria require re-examination. The answers are essential to neurology, organ transplantation and public policy.

In 1968, the medical community outlined specific neurologic tests that, if fulfilled, indicated a person was brain dead, creating an alternative definition of death accepted legally in every state. Since then, new diagnostic tests that measure brain activity more precisely, including PET scans and MRIs, have emerged. These new tests, while not used routinely to diagnose brain death, may have an important future role in this important medico-legal issue.

Photo: Mathew Sumner, Special To The Chronicle

Attorney Chris Dolan holds a news conference where he showed evidence that he says demonstrates that Jahi McMath is not brain dead in San Francisco on Thursday, Oct. 3, 2014.

Attorney Chris Dolan holds a news conference where he showed...

The exact moment life ends is a conceptual question: It can never be settled conclusively. Albert Einstein once observed that a single experiment could prove his most elaborate theory wrong. Likewise, the sad case of Jahi McMath and her “tell-tale heart” could fundamentally change the meaning of brain death.

Cory Franklin was director of medical intensive care at Cook County Hospital, where he was charged with the care of the most acutely ill non-trauma patients in Chicago’s urban hospital. He is the author of the forthcoming book, “Cook County ICU: 30 Years of Unforgettable Patients and Odd Cases,” (Chicago Review Press, 2015). To comment, submit your letter to the editor at www.sfgate.com/submissions.